Goulding admitted to MTV News that she is not necessarily a fan of Stephanie Meyer's vampire franchise, but understands what a huge opportunity she has to gain new listeners by lending her music to the final instalment.

"I'm not a Twi-hard but I take it for what it is; it's a cool thing and I can see why there's a huge fanbase. [And] they choose the best stuff for the soundtrack, so I'm really lucky to be a part of that!" she explained.

Goulding, who produced 'Bittersweet' with real-life boyfriend and fellow musician Skrillex, went on to say that the song was a perfect fit for the Twilight storyline, though that wasn't her intention upon writing it.

"Myself and Skrillex got together in the studio and started working on this song, and it's about waking up in the morning and hoping that the person feels the same way as you," she said.

"For some reason, every single lyric just ended up relating to this film. And I think when it was played at some point to the Twilight people, they were like, 'Oh my God!' So they asked us if we were interested in being on the soundtrack and we were like, 'Hell yeah!'"